1. Field of the Invention
The present invention relates to an ultrasonic transmitting unit which extends along a longitudinal axis and which can transmit an ultrasonic vibration from a proximal direction toward a distal direction. The present invention also relates to a manufacturing method of an ultrasonic transmitting unit.
2. Description of the Related Art
Ultrasonic treatment devices including ultrasonic transmitting units are disclosed in the specification of U.S. Patent Application Publication No. 2003/225332 and the specification of U.S. Pat. No. 5,391,144. Each of the ultrasonic transmitting units is provided with a vibration generating portion such as an ultrasonic vibrator which is configured to generate an ultrasonic vibration, a proximal side transmitting member to which the vibration generating portion is attached, and a distal side transmitting member (ultrasonic probe) which is attached to the proximal side transmitting member. The ultrasonic vibration generated in the vibration generating portion is transmitted to the proximal side transmitting member from the vibration generating portion, and transmitted to the distal side transmitting member from the proximal side transmitting member. That is, the ultrasonic vibration is transmitted from a proximal direction toward a distal direction. A horn which is configured to increase the amplitude of the ultrasonic vibration is provided in the proximal side transmitting member. An internal thread portion is formed in the proximal side transmitting member from a distal end thereof toward the proximal direction. An external thread portion is formed in the distal side transmitting member from a proximal end thereof toward the distal direction. The external thread portion is screwed to the internal thread portion, and the distal side transmitting member is thereby attached to the proximal side transmitting member.